RESUMEN

BACKGROUND AND PURPOSE: Predicting response to rtPA is essential in the era of endovascular therapy for stroke. The purpose of this study was to elucidate prognostic factors of early neurologic improvement and long-term outcome with respect to the development and reversion of leptomeningeal collaterals in recanalization therapy after acute ischemic stroke. MATERIALS AND METHODS: We analyzed consecutive patients with proximal MCA occlusion treated with rtPA from 2007 to 2012 at 2 hospital stroke centers. All patients routinely underwent brain MR imaging before rtPA. To assess the reversion of collateral signs, we included patients who underwent follow-up MR imaging. We assessed the development and reversion of collaterals by using a combination of 2 MR imaging collateral markers, the hyperintense vessel sign and the posterior cerebral artery laterality sign. Early neurologic improvement was defined as a decrease in the NIHSS score of ≥10 or a score of ≤2 at 24 hours of treatment. RESULTS: Early neurologic improvement was observed in 22 of 48 eligible patients. The development of collaterals at arrival (15/22 versus 9/26, P = .042) was significantly associated with early neurologic improvement. Multivariate analysis adjusting for other variables showed that the development of collaterals at arrival (OR, 4.82; 95% CI, 1.34-19.98; P = .015) was independently associated with early neurologic improvement. Reversion of collaterals was significantly associated with successful recanalization (P < .001), and multivariate analysis showed that the reversion of collaterals was an independent prognostic factor of long-term functional outcome (OR, 5.07; 95% CI, 1.38-22.09; P = .013). CONCLUSIONS: Our results indicate that the development of leptomeningeal collaterals plays a crucial role in achieving early neurologic improvement, and reversion of collaterals predicts a favorable outcome via arterial recanalization after rtPA treatment for acute stroke.

Asunto(s)

Encéfalo/irrigación sanguínea , Circulación Colateral/efectos de los fármacos , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/fisiopatología , Imagen por Resonancia Magnética/métodos , Terapia Trombolítica/métodos , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Examen Neurológico/efectos de los fármacos , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento

Asunto(s)

Histona Desacetilasas/genética , Cuerpos de Inclusión/genética , Cuerpos de Inclusión/patología , Cuerpos de Lewy/genética , Cuerpos de Lewy/patología , Proteínas Represoras/genética , Anciano , Anciano de 80 o más Años , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Masculino , Enfermedad de Parkinson/patología , Proteína SUMO-1/genética , Ubiquitina/genética , alfa-Sinucleína/genética

RESUMEN

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder characterized pathologically by the presence of ubiquitinated intranuclear inclusions (NII) in neuronal cells. We demonstrate that NIIs in both sporadic and familial NIID contained the small ubiquitin modifier-1 (SUMO-1) and the SUMOylation substrates promyelocytic leukaemia protein (PML) and histone deacetylase 4 (HDAC4). Both PML and SUMO-1 are major components of nuclear bodies (NBs), suggesting that the NIIs in NIID, as well as the intranuclear inclusions in polyglutamine diseases, might derive from these intranuclear functional domains that serve as sites for ubiquitin-related protein degradation. HDAC4 was also a major component of the NIIs. HDACs are transcriptional corepressors that regulate histone remodelling, and NBs are thought to be sites at which the level of histone acetylation is controlled. The presence of PML, SUMO-1 and HDAC4 in NIIs suggests that transcriptional activity regulated by histone acetylation might contribute to the disease process in NIID. In addition, we showed that another SUMOylation substrate, RanGAP1 is associated with NIIs only in the familial NIID patient. This might be explained by different pathogenetic mechanisms underlying subcategories of NIID, which is very heterogeneous.

Asunto(s)

Hipocampo/metabolismo , Cuerpos de Inclusión/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Proteína SUMO-1/metabolismo , Adulto , Femenino , Hipocampo/patología , Histona Desacetilasas/metabolismo , Humanos , Inmunohistoquímica , Masculino , Proteínas de Neoplasias/metabolismo , Enfermedades Neurodegenerativas/patología , Proteínas Nucleares/metabolismo , Proteína de la Leucemia Promielocítica , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina/metabolismo

RESUMEN

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant polyglutamine disorder presenting with progressive cerebellar ataxia and blindness. The molecular mechanisms underlying the selective neuronal death typical of SCA7 are unknown. We have established SCA7 cell culture models in HEK293 and SH-SY5Y cells, in order to analyse the effects of overexpression of the mutant ataxin-7 protein. The cells readily formed anti-ataxin-7 positive, fibrillar inclusions and small, nuclear electron dense structures. We have compared the inclusions in cells expressing mutant ataxin-7 and in human SCA7 brain tissue. There were consistent signs of ongoing abnormal protein folding, including the recruitment of heat-shock proteins and proteasome subunits. Occasionally, sequestered transcription factors were found. Activated caspase-3 was recruited into the inclusions in both the cell models and human SCA7 brain and its expression was upregulated in cortical neurones, suggesting that it may play a role in the disease process. Finally, on the ultrastructural level, there were signs of autophagy and nuclear indentations, indicative of a major stress response in cells expressing mutant ataxin-7.

Asunto(s)

Encéfalo/patología , Ataxias Espinocerebelosas/patología , Adulto , Ataxina-3 , Ataxina-7 , Encéfalo/metabolismo , Caspasa 3 , Caspasas/metabolismo , Línea Celular , Núcleo Celular/metabolismo , Niño , Cisteína Endopeptidasas/metabolismo , Activación Enzimática , Proteínas Fluorescentes Verdes , Proteínas de Choque Térmico/metabolismo , Humanos , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/ultraestructura , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Microscopía Confocal , Microscopía Electrónica , Persona de Mediana Edad , Complejos Multienzimáticos/metabolismo , Mutación , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Proteínas Nucleares , Complejo de la Endopetidasa Proteasomal , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Represoras , Ataxias Espinocerebelosas/genética , Ataxias Espinocerebelosas/metabolismo , Lóbulo Temporal/metabolismo , Lóbulo Temporal/patología , Células Tumorales Cultivadas

RESUMEN

At least 13 loci responsible for autosomal dominant cerebellar ataxia (ADCA) have been identified. Spinocerebellar ataxia 1, 2, 3, 6 and 7 are caused by translated CAG repeat expansions. However, in France, >30% of ADCAs are not explained by the known genes. Recently, analysis of the TATA box-binding protein (TBP) gene, one of the transcription factors known to contain a CAG/CAA repeat, in patients with progressive cerebellar ataxia revealed one sporadic case with 63 repeats. We examined this gene in 162 index cases with ADCA. An expanded repeat with 46 repeat units was detected in a single index case from Belgium. In this family, two affected members and six unaffected, but at-risk, individuals carried expanded alleles. Interestingly, the expanded repeat was stable during transmission. The main clinical features in six patients were cerebellar ataxia, dementia and behavioural disturbances with onset in their fourth to sixth decade. The main neuropathological finding was severe neuronal loss and gliosis in the Purkinje cell layer. Immunohistochemical analysis showed neuronal intranuclear inclusions containing expanded polyglutamine, indicating that this disease shares several features with other polyglutamine diseases. This study demonstrates that CAG/CAA repeat expansion in the TBP gene causes ADCA with dementia and/or psychiatric manifestations.

Asunto(s)

Ataxia Cerebelosa/genética , Proteínas de Unión al ADN/genética , TATA Box/genética , Factores de Transcripción/genética , Expansión de Repetición de Trinucleótido/genética , Adulto , Anciano , Atrofia , Encéfalo/patología , Ataxia Cerebelosa/patología , Femenino , Gliosis/genética , Gliosis/patología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Linaje , Proteína de Unión a TATA-Box

RESUMEN

Neuronal intranuclear inclusions (NIIs) found in CAG/polyglutamine-expansion disorders contain both expanded polyglutamine and the gene product without the CAG repeat. The gene product containing expanded polyglutamine has, therefore, been considered to be a major component of NIIs. In this immunohistochemical study, we showed recruitment of ataxin-2, ataxin-3 and TATA box binding protein (TBP) into NIIs of the pontine neurons of spinocerebellar ataxia type (SCA) 1, SCA2, SCA3 and dentatorubral-pallidoluysian atrophy brains. Triple-labeling immunofluorescence demonstrated colocalization of ataxin-2 and ataxin-3 in NIIs containing expanded polyglutamine, irrespective of the disease examined. These in vivo findings indicate that polyglutamine proteins recruited into NIIs are not restricted to their expanded form. Among these proteins, recruitment of ataxin-2 was least frequent in every case examined, suggesting that the rate of recruitment partly depends on the protein transported into NIIs. Because other proteins lacking polyglutamine motif were not detected in NIIs, it is suggested that the presence of polyglutamine is a prerequisite for these proteins to be recruited into nucleus and to form NIIs. Interaction between expanded and non-expanded polyglutamine may play roles during these processes.

Asunto(s)

Núcleo Celular/metabolismo , Cuerpos de Inclusión/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Péptidos/metabolismo , Puente/metabolismo , Degeneraciones Espinocerebelosas/metabolismo , Expansión de Repetición de Trinucleótido/genética , Ataxina-3 , Ataxinas , Núcleo Celular/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Inmunohistoquímica , Cuerpos de Inclusión/patología , Proteínas del Tejido Nervioso/genética , Neuronas/patología , Proteínas Nucleares , Péptidos/genética , Puente/patología , Puente/fisiopatología , Proteínas/genética , Proteínas/metabolismo , Proteínas Represoras , Degeneraciones Espinocerebelosas/genética , Degeneraciones Espinocerebelosas/patología , Proteína de Unión a TATA-Box , Factores de Transcripción/genética , Factores de Transcripción/metabolismo

RESUMEN

In an immunohistochemical study of Marinesco bodies--a neuronal intranuclear inclusion often seen in neurons of the substantia nigra of patients with hepatic encephalopathy--it was shown that one of the polyglutamine proteins, ataxin-3, is preferentially recruited into this inclusion, whereas other polyglutamine proteins (ataxin-2 and TATA box-binding protein) are not. This suggests that recruitment of each of the polyglutamine proteins may be differently regulated. Because this nuclear inclusion is thought to be formed in response to cellular stress, as occurs in hepatic encephalopathy, even in the absence of an expanded CAG/polyglutamine repeat, recruitment of ataxin-3 and ubiquitin into Marinesco bodies may represent a cellular response to noxious external stimuli unrelated to expanded CAG/polyglutamine.

Asunto(s)

Encefalopatía Hepática/patología , Cuerpos de Inclusión/patología , Proteínas del Tejido Nervioso/análisis , Péptidos/análisis , Sustancia Negra/patología , Anciano , Ataxina-3 , Núcleo Celular/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuronas/patología , Proteínas Nucleares , Proteínas Represoras

RESUMEN

Aggregations of the alpha1A-calcium channel protein have been previously demonstrated in spinocerebellar ataxia type 6 (SCA6). Here the authors show that small aggregates, labeled by a monoclonal antibody 1C2 that preferentially detects expanded polyglutamine larger than that in SCA6 mutation, are present mainly in the cytoplasm but also in the nucleus of Purkinje cells. Although the length of expansion is small in SCA6, the current finding might indicate that SCA6 conforms to the pathogenic mechanism(s) in other polyglutamine diseases.

Asunto(s)

Citoplasma/metabolismo , Péptidos/análisis , Células de Purkinje/metabolismo , Ataxias Espinocerebelosas/metabolismo , Encéfalo/metabolismo , Humanos , Péptidos/genética , Ataxias Espinocerebelosas/genética , Repeticiones de Trinucleótidos/genética

RESUMEN

Spinocerebellar ataxia 7 (SCA7) is a neurodegenerative disease caused by expansion of a CAG repeat in the coding region of the SCA7 gene. The disease primarily affects the cerebellum and the retina, but also many other central nervous system (CNS) structures as the disease progresses. Ataxin-7, encoded by the SCA7 gene, is a protein of unknown function expressed in many tissues including the CNS. In normal brain, ataxin-7 is found in the cytoplasm and/or nucleus of neurons, but in SCA7 brain ataxin-7 accumulates in intranuclear inclusions. Ataxin-7 is expressed ubiquitously, but mutation leads to neuronal death in only certain areas of the brain. This selective pattern of degeneration might be explained by interaction with a partner that is specifically expressed in vulnerable cells. We used a two-hybrid approach to screen a human retina cDNA library for ataxin-7-binding proteins, and isolated R85, a splice variant of Cbl-associated protein (CAP). R85 and CAP are generated by alternative splicing of the gene SH3P12 which we localized on chromosome 10q23-q24. The interaction between ataxin-7 and the SH3P12 gene products (SH3P12GPs) was confirmed by pull-down and co-immunoprecipitation. SH3P12GPs are expressed in Purkinje cells in the cerebellum. Ataxin-7 colocalizes with full-length R85 (R85FL) in co-transfected Cos-7 cells and with one of the SH3P12GPs in neuronal intranuclear inclusions in brain from a SCA7 patient. We propose that this interaction is part of a physiological pathway related to the function or turnover of ataxin-7. Its role in the pathophysiological process of SCA7 disease is discussed.

Asunto(s)

Empalme Alternativo/genética , Encéfalo/metabolismo , Núcleo Celular/metabolismo , Proteínas del Citoesqueleto/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/fisiología , ARN Mensajero/metabolismo , Secuencia de Aminoácidos , Animales , Ataxina-7 , Northern Blotting , Western Blotting , Encéfalo/citología , Células COS/metabolismo , Proteínas del Citoesqueleto/genética , Técnica del Anticuerpo Fluorescente , Glutatión Transferasa/metabolismo , Haplorrinos , Humanos , Técnicas para Inmunoenzimas , Hibridación Fluorescente in Situ , Cuerpos de Inclusión/metabolismo , Ratones , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/genética , Pruebas de Precipitina , Isoformas de Proteínas , Homología de Secuencia de Aminoácido , Técnicas del Sistema de Dos Híbridos , Levaduras/metabolismo , beta-Galactosidasa/metabolismo

RESUMEN

Recruitment of polyglutamine-containing proteins into nuclear inclusions (NIs) was investigated in neuronal intranuclear hyaline inclusion disease (NIHID). Some polyglutamine-containing proteins, ataxin-2, ataxin-3, and TATA box binding protein (TBP), as well as unidentified proteins with expanded polyglutamine tracts were recruited into NIs with different frequencies. Ataxin-3 was incorporated into most of the NIs and disappeared from its normal cytoplasmic localization, whereas only a small fraction of NIs contained ataxin-2 and TBP. The consistent presence of ataxin-3 in NIs could reflect a biological feature of wild-type ataxin-3, which is translocated into the nucleus under pathological conditions and participates in the formation of aggregates. Ataxin-2 also accumulated in the nucleus, but was not necessarily incorporated into NIs, suggesting that transport of these cytoplasmic proteins into the nucleus and their recruitment into NIs are not wholly explained by an interaction with a polyglutamine stretch and must be regulated in part by other mechanisms. The prevalence of ubiquitin-immunopositive NIs was inversely correlated to neuronal loss in all cases examined. This correlation could be explained if NI formation is a protective mechanism involving the ubiquitin-proteasome pathway. This hypothesis is supported by the finding that the polyglutamine epitope in the center of NIs was surrounded by ubiquitin.

Asunto(s)

Hialina/metabolismo , Cuerpos de Inclusión/patología , Enfermedades Neurodegenerativas/patología , Neuronas/patología , Proteínas/metabolismo , Adulto , Ataxina-3 , Ataxinas , Núcleo Celular/metabolismo , Núcleo Celular/patología , Núcleo Celular/ultraestructura , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Progresión de la Enfermedad , Resultado Fatal , Femenino , Glutamina/genética , Glutamina/metabolismo , Humanos , Hialina/ultraestructura , Inmunohistoquímica , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/ultraestructura , Sustancias Macromoleculares , Masculino , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Enfermedades Neurodegenerativas/diagnóstico , Enfermedades Neurodegenerativas/metabolismo , Neuronas/metabolismo , Neuronas/ultraestructura , Proteínas Nucleares , Proteínas/genética , Proteínas Represoras , Proteína de Unión a TATA-Box , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Repeticiones de Trinucleótidos/genética , Ubiquitinas/metabolismo

RESUMEN

Spinocerebellar ataxia 12 (SCA12) is an autosomal dominant cerebellar ataxia (ADCA) described in a single family with a CAG repeat expansion in the PPP2R2B gene. We screened 247 index cases, including 145 families with ADCA, for this expansion. An expanded repeat ranging from 55 to 61 triplets was detected in 6 affected and 3 unaffected individuals at risk in a single family from India. The association of the PPP2R2B CAG repeat expansion with disease in this new family provides additional evidence that the mutation is causative.

Asunto(s)

Ataxia Cerebelosa/genética , Adulto , Anciano , Alelos , Femenino , Francia , Humanos , India , Masculino , Persona de Mediana Edad , Linaje , Expansión de Repetición de Trinucleótido/genética

RESUMEN

Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3) is one of the dominantly inherited cerebellar ataxias. The gene responsible for the disease, a novel gene of unknown function, encodes ataxin-3 containing a polyglutamine stretch. Although it has been known that ataxin-3 is incorporated into neuronal intranuclear inclusions (NIIs) in neurons of affected regions, the relationship between NII formation and neuronal degeneration still remains uncertain. In the present study we show two different conditions in which ataxin-3 is recruited into the nucleus and suggest a process to form nuclear inclusions. In normal brains, wild-type ataxin-3 localizes within the ubiquitin-positive nuclear inclusion, the Marinesco body, indicating that ataxin-3 is recruited into the nuclear inclusion even in the absence of pathologically expanded polyglutamine. In MJD/SCA3 brains, immunohistochemical analyses with anti-ataxin-3 antibody, anti-ubiquitin antibody, and monoclonal antibody 1C2 known to recognize expanded polyglutamine revealed differences in frequency and in diameter among NIIs recognized by each antibody. These results were confirmed in the same inclusions by double immunofluorescent staining, suggesting that expanded ataxin-3 forms a core, thereby recruiting wild-type ataxin-3 into the nucleus around the core portion, and then followed by activation of the ubiquitin/ATP-dependent pathway. Recruitment of ataxin-3 into the nucleus and formation of nuclear inclusion under two different conditions suggest that ataxin-3 may be translocated into the nucleus under certain conditions stressful on neuronal cells such as aging and polyglutamine neurotoxicity.

Asunto(s)

Encéfalo/metabolismo , Núcleo Celular/metabolismo , Cuerpos de Inclusión/metabolismo , Enfermedad de Machado-Joseph/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Ataxina-3 , Encéfalo/patología , Núcleo Celular/patología , Humanos , Enfermedad de Machado-Joseph/patología , Proteínas Nucleares , Péptidos/metabolismo , Proteínas Represoras

RESUMEN

Neuronal intranuclear hyaline inclusion disease (NIHID) is a group of neurodegenerative disorders characterized by the presence of intranuclear inclusions in neurons (NIs). We report here clinicopathological findings of a 25-year-old female patient who died after 13 years of a clinical course characterized by progressive gait disturbance and movement disorders. Histological examination revealed widespread NIs with neuronal loss in restricted regions; neuronal loss was severe in the subthalamic nucleus, internal pallidum, substantia nigra, Edinger-Westphal nucleus and Purkinje cell layer. Quantification of the NIs combined with a graded evaluation of neuronal loss revealed an overall tendency for more severe neuronal loss to be accompanied by a lower frequency of NIs. A morphological similarity to the nuclear inclusions recently identified in several CAG repeat diseases prompted us to examine the immunolocalization of ubiquitin and expanded polyglutamine stretches, which demonstrated the presence of ubiquitin at the periphery of most NIs. An expanded polyglutamine stretch was seen in the center of limited number of NIs. These findings indicate that abnormal fragments such as expanded polyglutamine regions are incorporated into the inclusion, aggregated in its center, and thereby metabolized by a ubiquitin-dependent proteolytic pathway. Although it remains to be elucidated how the formation of NIs is related to neuronal degeneration, our findings suggest that NIs are formed in the process of sequestering or degrading abnormal protein fragments and formation of NIs may not be immediately toxic to neurons.

Asunto(s)

Hialina , Cuerpos de Inclusión/química , Cuerpos de Inclusión/patología , Neuronas/patología , Péptidos/análisis , Adulto , Anticuerpos , Resultado Fatal , Femenino , Humanos , Cuerpos de Inclusión/ultraestructura , Microscopía Electrónica , Degeneración Nerviosa/patología , Neuronas/ultraestructura , Péptidos/inmunología , Puente/patología , Ubiquitinas/análisis , Ubiquitinas/inmunología

Asunto(s)

Cuerpos de Inclusión/patología , Neuronas/patología , Ataxias Espinocerebelosas/patología , Humanos

RESUMEN

Abnormal CAG repeat expansion in the alpha1A voltage-dependent calcium channel gene is associated with spinocerebellar ataxia type 6, an autosomal dominant cerebellar ataxia with a predominant loss of the Purkinje cell. A reverse transcriptase-polymerase chain reaction analysis of mRNA from mouse Purkinje cells revealed a predominant expression of the alpha1A channel lacking an asparagine-proline (NP) stretch in the domain IV (alpha1A(-NP)). Human alpha1A channels carrying various polyglutamine length with or without NP were expressed in HEK293 cells, and channel properties were compared using a whole-cell voltage clamp technique. alpha1A(-NP), corresponding to P-type channel, with 24 and 28 polyglutamines found in patients showed the voltage dependence of inactivation shifting negatively by 6 and 11 mV, respectively, from the 13 polyglutamine control. Contrarily, the alpha1A channel with NP (alpha1A(+NP)), corresponding to Q-type channel, with 28 polyglutamines exhibited a positive shift of 5 mV. These results suggest that altered function of alpha1A(-NP) may contribute to degeneration of Purkinje cells, which express predominantly alpha1A(-NP), due to the reduced Ca(2+) influx resulting from the negative shift of voltage-dependent inactivation. On the other hand, other types of neurons, expressing both alpha1A(-NP) and alpha1A(+NP), may survive because the positive shift of voltage-dependent inactivation of alpha1A(+NP) compensates Ca(2+) influx.

Asunto(s)

Canales de Calcio Tipo P/genética , Péptidos/metabolismo , Degeneraciones Espinocerebelosas/genética , Animales , Secuencia de Bases , Canales de Calcio Tipo P/química , Canales de Calcio Tipo P/fisiología , Canales de Calcio Tipo Q/genética , Células Cultivadas , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Mutación , Conejos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa

RESUMEN

Spinocerebellar ataxia type 2 (SCA2) is associated with an expansion of CAG/polyglutamine-repeat of a gene of unknown function. We performed an immunohistochemical study to identify the immunolocalization of the disease protein ataxin-2 in normal and SCA2 patients. Although normal and expanded ataxin-2 were ubiquitously localized to the cytoplasm of neurons, ubiquitinated intranuclear inclusions were observed selectively in 1-2% of neurons of affected brain regions except the cerebellum. Triple-labeling immunofluorescence revealed that ataxin-2, expanded polyglutamine and ubiquitin were colocalized to these neuronal intranuclear inclusions (NIs), indicating that SCA2 shares morphological characteristics common to other neurological disorders associated with an expansion of CAG/polyglutamine-repeat. Lack of NIs in the cerebellar lesion, however, suggests the discrepancy between formation of NIs and neuronal degeneration in SCA2.

Asunto(s)

Cuerpos de Inclusión/patología , Neuronas/patología , Ataxias Espinocerebelosas/patología , Ataxinas , Cadáver , Humanos , Inmunohistoquímica , Proteínas del Tejido Nervioso , Péptidos/metabolismo , Proteínas/metabolismo , Valores de Referencia , Ataxias Espinocerebelosas/metabolismo , Distribución Tisular , Ubiquitinas/metabolismo

RESUMEN

Spinocerebellar ataxia type 6 (SCA6) is one of the eight neurodegenerative diseases caused by a tri-nucleotide (CAG) repeat expansion coding polyglutamine (CAG repeat/polyglutamine diseases) and is characterized by late onset autosomal dominant cerebellar ataxia and predominant loss of cerebellar Purkinje cells. Although the causative, small and stable CAG repeat expansion for this disease has been identified in the [alpha]1A voltage-dependent calcium channel gene (CACNA1A), the mechanism which leads to predominant Purkinje cell degeneration is totally unknown. In this study, we show that the calcium channel mRNA/protein containing the CAG repeat/polyglutamine tract is most intensely expressed in Purkinje cells of human brains. In SCA6 brains, numerous oval or rod-shaped aggregates were seen exclusively in the cytoplasm of Purkinje cells. These cytoplasmic inclusions were not ubiquitinated, which contrasts with the neuronal intra-nuclear inclusions of other CAG repeat/polyglutamine diseases. In cultured cells, formation of perinuclear aggregates of the channel protein and apoptotic cell death were seen when transfected with full-length CACNA1A coding an expanded polyglutamine tract. The present study indicates that the mechanism of neurodegeneration in SCA6 is associated with cytoplasmic aggregations of the [alpha]1A calcium channel protein caused by a small CAG repeat/polyglutamine expansion in CACNA1A.

Asunto(s)

Encéfalo/metabolismo , Canales de Calcio/biosíntesis , Degeneraciones Espinocerebelosas/metabolismo , Animales , Apoptosis , Encéfalo/patología , Canales de Calcio/genética , Células Cultivadas , Citoplasma/metabolismo , Humanos , Células PC12 , Péptidos/metabolismo , Células de Purkinje , ARN Mensajero/biosíntesis , Ratas , Degeneraciones Espinocerebelosas/genética , Degeneraciones Espinocerebelosas/patología , Expansión de Repetición de Trinucleótido/genética

RESUMEN

V-1 protein is a novel member of the cdc10/SWI6 motif-containing protein superfamily several members of which have been demonstrated to play crucial roles in the regulation of intracellular signaling. In the present study we examined the distribution of V-1 mRNA in the murine central nervous system (CNS). Northern analysis revealed the expression of V-1 mRNA in various regions of the brain with the following rank order: hippocampus, cerebellum > cerebral cortex, olfactory bulb, medulla oblongata, pons > thalamus. In situ hybridization also showed that V-1 mRNA is widely distributed in various regions of the brain, with parallel expression levels to those revealed by Northern analysis. Immunohistochemical analysis revealed that the V-1 protein exists in various types of neurons, mainly in cell bodies but also in dendrites, axons and possibly in synaptic areas. These expression patterns of the V-1 gene in the murine CNS suggest that the V-1 protein performs some common function in different classes of neurons. We found no significant difference in the expression level of V-1 mRNA in cerebellar granule cells between the control and mutant mice of Purkinje cell degeneration (pcd). In comparison with our previous data obtained in another mutant, staggerer, we discussed the effects of target deprivation on the expression of V-1 mRNA in cerebellar granule cells.

Asunto(s)

Sistema Nervioso Central/metabolismo , Corteza Cerebral/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Proteínas del Tejido Nervioso/metabolismo , Animales , Autorradiografía , Western Blotting , Expresión Génica/genética , Inmunohistoquímica , Hibridación in Situ , Masculino , Ratones , Ratones Endogámicos , Mutación , Ratas , Ratas Wistar

Asunto(s)

Paraparesia Espástica Tropical/genética , Priones/genética , Humanos , Mutación

RESUMEN

Two sisters with familial Alzheimer's disease developed spastic gait disturbance as an initial manifestation. Their gait disturbance progressed gradually, followed by dementia a few years later. Post-mortem examination of one of the patients disclosed degeneration of the thalamus and corticospinal tract in addition to numerous senile plaques and neurofibrillary tangles in the neocortex, both of which were confirmed by immunohistochemistry. This is the first report in which clinicopathological evaluation is sufficient to establish a new variant of Alzheimer's disease presenting initially as spastic tetraplegia.

Asunto(s)

Enfermedad de Alzheimer/complicaciones , Espasticidad Muscular/etiología , Cuadriplejía/etiología , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Encéfalo/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Espasticidad Muscular/patología , Linaje , Cuadriplejía/patología